Fractures of the distal end of the radius should be

FRACTURES OF THE DISTAL END OF THE RADIUS TREATED BY INTERNAL FIXATION AND EARLY FUNCTION A PRELIMINARY REPORT OF 20 CASES DANIEL A. RIKLI, PIETRO REGAZZONI From the University Hospital, Basel, Switzerland Fractures of the distal end of the radius should be treated on the same principles as other fractures involving joints. Displaced articular fractures require open reduction to allow anatomical reconstruction of both the radiocarpal and the radio-ulnar joints. For extra-articular fractures with severe comminution and shortening this enables the radial length to be re-established achieving radio-ulnar congruency. Stable internal fixation can be achieved with two 2.0 AO titanium plates placed on each of the lateral and the intermediate columns of the wrist at an angle of 50 to 70. This gives good stability despite the tiny dimensions of the plates, and allows early function. We report a series of 20 fractures treated by this method of internal fixation with satisfactory results in all. J Bone Joint Surg [Br] 1996;78-B:588-92. Received 12 December 1995; Accepted 25 January 1996 D. A. Rikli, MD P. Regazzoni, MD, Professor Department of Surgery, University Hospital, Spitalstrasse 21, CH-4031 Basel, Switzerland. Correspondence should be sent to Dr D. A. Rikli. 1996 British Editorial Society of Bone and Joint Surgery 0301-620X/96/41214 $2.00 The management of fractures of the distal end of the radius has changed since Cassebaum (1950) supported Abraham Colles statement that a patient with a Colles fracture will not have pain or serious functional disability despite considerable deformity. This is no longer acceptable; McQueen and Caspers (1988) have shown a clear correlation between anatomical and functional results. Secondary reconstruction is difficult (Fernandez 1982, 1993) and repetitive manipulations appear to increase the risk of algodystrophy. It therefore seems that fractures of the distal radius should be treated by the principles usually applied to other articular fractures. Extra-articular fractures (type A in the AO classification) require avoidance of malunion with angulation and shortening. Malalignment results in limitation of movement (Fernandez 1993), changes in load distribution (Short et al 1987), midcarpal instability (Taleisnik and Watson 1984) and an increased risk of osteoarthritis of the radiocarpal joint. Radial length is also an important prognostic factor (Aro and Koivunen 1991; Trumble, Schmitt and Vedder 1994); loss results in a painful restriction of range of movement due to incongruency of the distal radio-ulnar joint, impingement of the triangular fibrocartilage and subluxation of the ulnar head leading to degenerative arthritis (Fernandez 1988; Hagert 1994). Intra-articular fractures (AO types B and C) with a step of over 2 mm in the radiocarpal joint inevitably result in osteoarthritis and functional impairment (Knirk and Jupiter 1986). It is therefore important to reconstruct the joint surface and make it congruent, and many methods of reconstructing the radiocarpal joint have given good results (Melone 1986; Axelrod et al 1988; Bradway, Amadio and Cooney 1989; Fernandez and Geissler 1991; Jupiter and Lipton 1993). The work of Frykman (1967) showed that the radio-ulnar joint is an important factor in the treatment of fractures of the distal end of the radius (Melone 1986; Fernandez 1988), but despite this and the high rates of degenerative arthritis of the distal radio-ulnar joint after distal radial fractures (Altissimi et al 1986), these treatments have been based solely on correction of the radiocarpal joint. For comminuted intra-articular fractures most authors combine fixation with Kirschner wires, cancellous bone graft and external fixation after closed or open reduction and report good to excellent results (Axelrod et al 1988; Bradway et al 1989; Edwards 1991; Fernandez and Geissler 1991; Jupiter and Lipton 1993; Trumble et al 1994). The long period of immobilisation and prolonged rehabilitation, however, can be a major problem in this type of management. The use of primary cancellous bone graft and immobilisation with an external fixator for a relatively short period of two to three weeks is a new and interesting concept (Leung et al 1990). As for any other articular fracture, the treatment of an intra-articular fracture of the distal end of the radius should provide meticulous reconstruction of the joint surface, rigid internal fixation and early functional aftertreatment (Jupiter and Lipton 1993; Palmer 1993). The distal radius and the 588 THE JOURNAL OF BONE AND JOINT SURGERY

FRACTURES OF THE DISTAL END OF THE RADIUS TREATED BY INTERNAL FIXATION AND EARLY FUNCTION 589 Fig. 1b Fig. 1a The proximal wrist joint; showing the medial (mc), intermediate (ic) and lateral (lc) columns. dista ulna form a three-column biomechanical construction. The medial column is the distal ulna, the triangular fibrocartilage and the distal radio-ulnar joint. The intermediate column is the medial part of the distal radius, with the lunate fossa and the sigmoid notch. The lateral column is the lateral radius with the scaphoid fossa and the styloid process (Fig. 1). A dorsally displaced fracture of the distal radius shows not only dorsiflexion in the sagittal plane, but also radial deviation in the frontal plane and supination in the transverse plane. Stabilisation after reduction requires buttressing of the intermediate column as well as the lateral column, but as yet no properly designed implants are available (Jupiter and Lipton 1993). Internal fixation by an AO 3.5 titanium plate (T) (Stratec Medical, Oberdorf, Switzerland) which was originally designed for flexion fractures, is not satisfactory because the size of the plate and screws is not appropriate, and Lister s tubercle has to be removed. Interference with the extensor tendons can lead to synovitis and ruptures (Pfeiffer, personal communication, 1994). To provide buttressing of both columns, in 1993 the senior author (PR) introduced a method of open reduction and internal fixation by using two AO 2.0 T-plates (Stratec Medical, Oberdorf, Switzerland) placed on the intermediate and the lateral columns at an angle of 50 to 70 to each other which enhances the stability of the fixation and neutralises rotational forces (Fig. 2). If there is also instability of the medial column due to a subcapital fracture of the ulna or avulsion of the triangular fibrocartilage, the third column is stabilised by plating the distal ulna or by a tension-band repair of an avulsed meniscus. This enables both the radiocarpal and the radio-ulnar joints to be perfectly restored (Fig. 3). The small implants correspond to the small fragments and Lister s tubercle can be left intact. They can always be completely covered with a periosteal flap and parts of the extensor retinaculum, and early functional aftertreatment is possible as soon as swelling has subsided and the wound has healed. Fig. 2 Diagram of internal fixation by double buttressing. The implants are placed at an angle of 50 to 70 to each other. VOL. 78-B, NO. 4, JULY 1996

590 D. A. RIKLI, P. REGAZZONI Fig. 3a Radiographs of a 48-year-old patient with an intra-articular two-column fracture with a large dorso-ulnar fragment and metaphyseal comminution. Figure 3a Before operation. Figure 3b Two months after open reduction and internal fixation with a 2.0 T-plate and a 2.0 DCP. There is perfect congruity of the distal radio-ulnar joint. Fig. 3b PATIENTS From September 1993 to November 1994 the senior author (PR) treated 19 patients with 20 fractures of the distal end of the radius by open reduction, internal fixation with 2.0 titanium implants and early functional exercises. There were 12 women of mean age 60 years (29 to 80) and seven men of mean age 38 years (24 to 68). Fourteen of the 20 fractures were intra-articular (AO type B or C) and six were extra-articular (AO type A). Six of the operations were primary procedures and 14 were secondary after the failure of conservative or operative treatment in acute injuries. One was an osteotomy for a malunited fracture. The patients were reviewed and examined by an independent author (DAR) after a minimum follow-up of six months. The evaluation included analysis of the preoperative and postoperative radiographs and measurements of the range of movement and grip strength compared with the uninjured side in all except the bilateral case. Operative technique. Through a straight dorsal incision, the third extensor tendon sheath is opened parallel to the extensor pollicis longus (EPL) tendon, taking care to preserve the distal part of the extensor retinaculum over the course of the EPL tendon. The bony surface of the dorsum of the radius is exposed through the floor of the tendon sheath at the edge of Lister s tubercle. Limited subperiosteal dissection is used to reveal and understand the fracture and prepare the anticipated site of the implants. A THE JOURNAL OF BONE AND JOINT SURGERY

FRACTURES OF THE DISTAL END OF THE RADIUS TREATED BY INTERNAL FIXATION AND EARLY FUNCTION 591 cortical shell is carefully lifted to expose the metaphyseal defect and fill it with bone graft. The radial length is adjusted. Careful traction on the thumb helps to reduce the radial styloid and in many cases it is best to buttress this fragment first, using a precontoured 5- to 6-hole 2.0 DCP placed on the dorsolateral radius (lateral column), as far lateral as the brachioradialis insertion if needed. The plate is fixed first by a single screw in the most distal hole related to the proximal fragment, close to the fracture. A 6-hole 2.0 T-plate is then precontoured to fit the dorso-ulnar side of the radius to control fragments in the intermediate column. This plate is also fixed in a preliminary fashion by a single screw close to the fracture on its proximal side. The reduction of the fracture and the position of the implants are studied by image intensifier with special attention to the congruency of the radiocarpal and the radioulnar joints. The osteosynthesis is then completed, usually by first placing the most proximal screw in both plates, to block any rotation of the implants. Two screws are then placed distally in each plate, and smaller bone fragments are squeezed under them. Final control radiographs are taken. The distal part of the T-plate is covered with periosteum or an extensor retinaculum flap if this is needed, to avoid interference with the extensor tendons. There should be no contact between the implants and the tendons. The EPL tendon is replaced anatomically, on the ulnar side of Lister s tubercle, held by the preserved distal part of the extensor retinaculum. Suction drainage is used for 24 hours, and a volar splint for two to four days for the wrist, but the fingers, elbow and shoulder are mobilised from the first day under the supervision of a physiotherapist. Active assisted mobilisation of the wrist including pronation and supination begins as soon as pain and swelling have subsided and the wound is clean. This continues on an outpatient basis. After check radiographs at four and eight weeks, strengthening exercises with increasing load are started once there is evidence of fracture union. Physiotherapy is usually stopped at three months although further functional improvement can be expected for much longer. If implant removal is considered necessary this should be performed no later than six to 12 months postoperatively. Due to the strong incorporation of titanimum implants into the bone removal can be very difficult after more than one year. RESULTS All 20 fractures united and consolidated with no secondary displacement, and no superficial or deep infection. One patient with a grossly displaced C2.3 fracture with radioulnar dissociation developed severe algodystrophy of the injured hand. At the latest review the disease was still active with pain and a very limited range of movement. The fracture had had preliminary fixation with an external fixator and had been remanipulated before the internal fixation. Table I. Range of movement (percentage) compared with the uninjured side in 17 patients Range of movement 100 90 to 99 80 to 89 70 to 79 60 to 69 Dorsiflexion 9 4 2 2 Palmar flexion 4 4 3 5 1 Ulnar deviation 13 3 1 Radial deviation 10 1 1 5 Supination 5 3 6 2 1 Pronation 13 3 1 Table II. Pain in 19 patients with 20 fractures Number None 10 Occasional with major activity 6 Always with major activity 3 Occasional with minor activity 1 Always with minor activity 0 No activity 0 Table III. Grip strength (percentage) compared with the uninjured side in 17 patients Strength >100 90 to 99 80 to 89 70 to 79 60 to 69 Fx dominant side 3 1 2 2 2 Fx non-dominant side 1 1 2 3 Of the remaining 17 patients (excluding the patient with bilateral fractures) 15 had 80% or more of the range of dorsiflexion in their uninjured wrist, 11 had 80% or more palmar flexion, 17 had 80% or more ulnar deviation, 12 had 80% or more radial deviation, 14 had 80% or more supination, and 16 had 80% or more pronation (Table I). Sixteen patients had been able to resume their former activities without restrictions; two had slight restrictions and one was permanently disabled because of an associated severe brain injury. Sixteen patients had no pain or only slight pain with heavy work. Three always have some pain with heavy work but do not take any analgesics. The patient with algodystrophy has pain on even minor activity (Table II). Ten of the 17 patients had 80% or more strength compared with the uninjured side; the other seven had at least 60% (Table III). On the classification of Stewart, Innes and Burke (1985) the anatomical results were excellent in 18 wrists and good in two. Fifteen wrists showed no signs of osteoarthritis, that is grade 0 on the scale of Knirk and Jupiter (1986). Four had developed a grade-1 arthritis but were free from symptoms and one had a pre-existing grade-2 arthritis. VOL. 78-B, NO. 4, JULY 1996

592 D. A. RIKLI, P. REGAZZONI DISCUSSION Fractures of the distal end of the radius should be treated on the same principles as any other fracture near or into a joint. Extra-articular fractures require as careful consideration as intra-articular fractures because malunion changes the carpal architecture, producing midcarpal instability, alteration in load distribution which may lead to a prearthritic state and incongruence of the distal radio-ulnar joint. The AO 3.5 T-plate was designed to treat flexion fractures. It is placed on the flat volar surface of the distal radius underneath the pronator quadratus where it is covered by this muscle and is not in contact with tendons and nerves. These T-plates have subsequently been used on the dorsum of the distal radius for extension fractures, but gave rise to two problems. First, the biomechanics of flexion and of extension fractures of the distal radius are different. Flexion fractures usually have a compact distal fragment which must be buttressed on the volar side to counter the pull of the flexor tendons. By contrast, the displacement of extension fractures is in three different planes and buttressing is needed for the intermediate column as well as the lateral column. A 3.5 T-plate can be used for the intermediate column but not for the lateral column. Secondly, the dorsum of the radius has a more complex anatomy; the surface of the radius is made tent-shaped by Lister s tubercle and the extensor tendons are in close proximity. In addition, there are usually several small and friable metaphyseal and articular fragments. A 3.5 T-plate is too big for these small fragments and it is difficult to obtain a good purchase in comminuted distal fragments, which may be rotationally unstable. An external fixator may be valuable in some cases, and displaced fragments are sometimes reduced by ligamentotaxis, but external fixation precludes early function and in comminuted articular fractures with impacted fragments indirect reduction is not possible. The use of 2.0 plates and screws allows more accurate treatment: after reconstruction of the joint under direct vision and re-establishment of radial length, both intermediate and lateral columns can be buttressed and cancellous bone graft may be added where it is needed. The 2.0 screws usually give a good purchase in the distal fragment; the risk of damaging brittle fragments is minimal. Lister s tubercle is left intact and there is no interference with the extensor tendons since the plates and screws can always be covered with a periosteal flap. These implants are especially useful for very short fragments, such as Barton-type fractures. Early functional treatment can start as soon as the wound is stable. Our results in the first small group of 20 patients have been encouraging. The operation is technically demanding but provides an excellent method of treatment for difficult distal fractures of the radius. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. REFERENCES Altissimi M, Antenucci R, Fiacca C, Mancini GB. Long-term results of conservative treatment of fractures of the distal radius. Clin Orthop 1986;206:202-10. Aro HT, Koivunen T. Minor axial shortening of the radius affects outcome of Colles fracture treatment. J Hand Surg Am 1991; 16:392-8. Axelrod T, Paley D, Green J, McMurtry RY. Limited open reduction of the lunate facet in comminuted intraarticular fractures of the distal radius. J Hand Surg Am 1988;13:372-7. Bradway JK, Amadio PC, Cooney WP. Open reduction and internal fixation of displaced, comminuted intra-articular fractures of the distal end of the radius. 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Palmer AK. Fractures of the distal radius. In: Green DP, Hotchkiss RN, eds. Operative Hand Surgery. Vol. 1, 3rd edition. New York, etc: Churchill Livingstone, 1993:929-71. Short WH, Palmer AK, Werner FW, Murphy DJ. A biomechanical study of distal radial fractures. J Hand Surg [Am] 1987;12-A: 529-34. Stewart HD, Innes AR, Burke FD. Factors affecting the outcome of Colles fracture: an anatomical and functional study. Injury 1985;16:289-95. Taleisnik J, Watson HK. Midcarpal instability caused by malunited fractures of the distal radius. J Hand Surg (Am) 1984;9:350-7. Trumble TE, Schmitt SR, Vedder NB. Factors affecting functional outcome of displaced intraarticular distal radius fractures. J Hand Surg Am 1994;19:325-40. THE JOURNAL OF BONE AND JOINT SURGERY